Into the modern society, the interaction between human and display become an important way for people to access and share information, such display including liquid crystal display due to good screen reproducibility and it has become the mainstream of the display. The basic principle of the liquid crystal display is to irradiate the liquid crystal cell by a backlight, and the liquid crystal cell realizes the size control of the grayscale by light valve through the change of the polarization state of the liquid crystal molecules driven by the TFT array. The display is usually in a state of screen off when it is under an informal working state; however, people gradually come up with the corresponding functions for displaying the time and message in a brief form even under the screen-off state.